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Everything posted by juanrga

  1. In the first place, a black hole is not a singularity; a black hole contains a singularity. In the second place, they would not be named "black holes", because a black hole is a concept that arises from a given theory as general relativity. A possible name could be black compact object. We would be able to measure the mass, charge and angular momentum of those objects. We would be able to measure gravitational lensing and X-ray emissions in binary systems.
  2. It is evident for me that you quoted Einstein as authority in your first post, instead of giving technical arguments on why you disagree. You continue now without giving any technical argument to me and merely appeal to authority again with your "to concern ourselves with the architect of general relativity", "Einstein was the one who created GR"... Moreover, your appeal to authority is not even well-supported by the history of physics. General relativity was developed by at least three main authors. The attempt to present Einstein as the sole creator of general relativity is a typical physicists' oversimplification, with many historians disagreeing. Since this is not a thread about the history of relativity, I will not give more details.
  3. Nobody is proposing MOND as "the last word on gravity" and extensions to MOND are under active research. Yes, most astronomers and theorists believe that there is something physical there out and name it "dark matter", somewhat as in the past most astronomers and physicists believed that Vulcan existed. The Modified Newton Gravity Models show that you can explain the observed phenomena without any need to introduce the hypothesis of a new and mysterious kind of matter with odd properties. And this is in agreement with the null results of the hundred of experiments that have searched the hypothetical "dark matter" and have not found it... just as Vulcan, the hypothetical planet, was never found
  4. Sorry, but Einstein did many mistakes [1] and your appeal to authority (your quote does not give any technical argument) is not enough. I have read Einstein's original works on relativity, including his textbook and this could not be used today even for an introductory course in relativity! It is not true that the concepts of physics have always been geometrical. This is plain false and this why we have geometrical optics vs physical optics, for instance (with the first being an approximation to the latter). The reason for which gik is a metric and describes the geometry of spacetime, whereas the electromagnetic field Fik do not, has nothing to see with history, but with their respective physical and mathematical properties. General relativity relies on the principle of equivalence or geometrisation, reason for which general relativity is often named geometrodynamics (see MTW textbook). [1] A beautiful article by S. Weinberg, revising some Einstein's mistakes, was published in Physics Today http://physicstoday....tml?bypassSSO=1
  5. Normal hemoglobin values vary according to age and sex, pregnancy, the altitude where you live, if you smoke... If you donate blood they will do you a test for free
  6. Biological determinism can be in disagreement with ethics, but the main problem is that determinism (biological, physical or other) is an outdated philosophical idea that ignores recent scientific developments: non-deterministic chaos, emergence...
  7. Blood is red due to hemoglobin molecules. These molecules contain iron ions
  8. If you are "not interested in theories" then you are not interested in any answer really, because any "proof" or "experiment" needs to be interpreted within the framework of some theory. Without theories we do not can even define what is an "electron", what is an "orbit", what means "an electron goes from one atom to another", what is a "collision"... The concepts of electron in Maxwell-Lorentz theory, Bohr theory, Lewis theory, quantum mechanical theory, Dirac theory, quantum electrodynamics theory are different. For instance, an electron in Dirac theory has a property named spin, an electron in in Maxwell-Lorentz theory do not have spin. An electron in Bohr theory belong to a given atom, and electron in Lewis theory can belong to two atoms at once, etcetera.
  9. It is not right that only matter is affected by gravity. Light is also affected. For instance light bends around Sun due to gravity. Neither "light is made up of matter".
  10. Those definitions appealing to "disorder" often confound the thermodynamic concept of entropy with the informational concept of entropy. The opposite phenomenon that you report is creation of structures. It is studied with the concept of entropy as well.
  11. There is not magnetic fields per se but electromagnetic fields. An electromagnetic field is a physical system, which is macroscopically characterized by its properties such as energy, momentum... A electromagnetic field spread over space. From a microscopic point of view an electromagnetic field is an infinite collection of quantum harmonic oscillators.
  12. It depends on what do you mean by mass. If by mass you mean, for example, the m that appears in (1/2 mv2), this mass is constant. What varies is the energy of the atom not its mass m. This is the same for an electron. The mass of an electron me does not vary when the electron is accelerated by absorbing a photon. Some people uses an old concept of mass (sometimes named relativistic mass) M, which varies with energy as M = E/c2. This M varies when energy E varies.
  13. As mathematical physicists Neumaier has pointed many-worlds See also http://www.mth.kcl.ac.uk/~streater/lostcauses.html#XII
  14. Gravitational time dilation is a subset of the general concept of time dilation
  15. This is not internal energy, but rest (mechanical) energy. Internal energy U is a different kind of energy.
  16. You do not give any detail (input values, uncertainties...) about your empirical formula, but what really surprises me is that you title this as "without relativity" when I can see a c2 factor in your empirical formula .
  17. It depends: in Newtonian gravity it is a force as the electromagnetic force. In general relativity it cannot be a force, because this is a geometric theory. What we know is that the fundamental nature of gravity has to be quantum and in a quantum formulation the concept of interaction is not reduced to the classical concept of force.
  18. Dark matter is the Vulcan planet of the 21st century All the direct searches of dark matter have found nothing during the last decades. And all the 'indirect evidence' of the existence of dark matter has been discredited in recent years as well. For example the Bullet Cluster cannot be explained by dark matter, although some years ago it was considered the best 'evidence' of its existence. The past year a new galactic test resulted in another fiasco for the dark matter hypothesis http://blogs.nature....02/post_73.html http://www.bbc.co.uk...onment-12571965
  19. Yes, I suppose that different people can be using the term in different ways. I assumed that was being used in the IUPAC sense, which is (their official definition of molecularity): It is this belief on the real existence of unimolecular elementary reactions, which I cast into doubt by technical reasons.
  20. Although the fundamental processes on nature are bi-'molecular' (so far as I know), you can get kinetics of order one, two, three, depending on the mechanism and experimental conditions. I wrote molecular between quotes, because it also applies to unstable particles and radioactive nuclei. What happens is that the real de-excitation or relaxation process can be almost always linearized, as approximation, and then you get a master or kinetic equation of order one. The usual kinetic equation for decay of unstable A* --> P dP/dt = k[A*] is derived, as approximation, to a underlying 'master' equation for a fundamental process (A* + E --> P + E') after assuming E'=E and then taking E to be in a thermal state. The Redfield equation, used in NMR, is derived in a similar way from a more fundamental bi-'molecular' expression.
  21. Yes. Precisely I have been recently working in a encyclopedic article about science, and I gave a new definition of science that does not assume a human nature for the scientist. The main academic reference I cite is: The Automation of Science 2009: Science 324(5923), 85–89. King, Ross D.; Rowland, Jem; Oliver, Stephen G.; Young, Michael; Aubrey, Wayne; Byrne, Emma; Liakata, Maria; Markham, Magdalena; Pir, Pinar; Soldatova, Larisa N.; Sparkes, Andrew; Whelan, Kenneth E.; Clare, Amanda.
  22. A molecule alone cannot do anything. It is only when it interact with some other molecular entity, nuclei, or particle that it can change. All molecular mechanisms are bimolecular. Unimolecular reactions are really bimolecular! For instance, the transformation of cyclo-propane into propene is approx. modelled as unimolecular process A --> B but the real mechanism (Lindemann-Hinshelwood mechanisms) is A + A --> A + A* --> A + B which involves two molecules.
  23. There is already computers as Adam discovering laws. In far future it is likely that human scientists get replaced by computer scientists.
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